Telephone receiver



Feb. 16 1926.- l 1,573,754

D. WALD TELEPHONE RECEIVER original Filed June 50,1922

By j/W A TTOHNEYS Patentea Feb. 16, 1926.

UNITED STATES PATENT OFFICE.

DAVID WALD, OF BROOKLYN, NEW YORK.

TELEPHONE RECEIVER.

Application led' .Tune 30, 1922, Serial No. 572,044. IRenewed Decemberil, 1925.' g

To aZZ whom t may concern.'

Be it known that I, DAVID `WALD, a citizen of the United States, and a resident of the city of New York, borough of Brooklyn, in

the county of Kings and State of New York,

\ have invented a new and Improved Telephone Receiver, of which the following is a full, clear, and exact description.

This invention relates to a receiver for use in the reception of electrical impulses such as telephone currents, and has for an object the provision of a construction in which the vibration of a diaphragm in respone to lcurrent frequencies over ay wide range can be placed with a minimum amount of distortion.

Another object resides din the pro-vision of means =whereby the above object can be achieved, with a construction involving a minimum modification of the .present type of receiver, whereby economy of manufacture is achieved.

A further object resides1 in the particular construction and arrangement of partsl be adopted without departing fromthe spirit of the invention.

The drawings illustrate onelform which my invention may assume, and this application thereof includes a vcylindrical 'shelllO andi-an outside cap 11 related' inthe usual manner to veach other by cap screws 12.4 The shell 10 isprovidedwith an interiorly extending annular iange 13 forming a -shoulder onwhich a gasket 14, preferably. of

rubber, is disposed. On this gasket a'dia phragm 15, preferably of mica, is laid and over the edge of lthis diaphragm 'another gasketl, preferably of rubber, is disposed, the ymica diaphragm being thereby sup'A pgrted withinthe shell 10 .between the .rub-

r providedv withV a` downwardly extending angaskets'lljand 16.` The outer cap isnular ange 17 which bears" against the upper gasket 16, and by the adjusting action of the cap screws 12 will tightly clampl the mica diaphragm 15 between the gaskets. v

A second diaphragm 18, preferably of steel or other magnetic material, is .disposed within the shell 10 Aand bears 1 against the lower'face of the shoulder 13. This steel diaphragm is connected by suitablemeans, such as a pin 19, preferably to the central pointof the mica diaphragm 15. The end of the pin is threaded through a -anged bushing sleeve 20 which has a portion threaded to receive a tightening nut 21. Of course, the connection between the steel and the mica diaphragms may be made vin a variety of ways without departing from the spirit of the invention, which involves the combination with a diaphragm responsive to magnetic inliuences, such as a steel diaphragm, of a second diaphragm,.such as a whereby the combined vibration of the two diaphragms will result in a more uniform production of sound waves from the re- -ceiver and in this way reduce the distortion generally consequent to the action of the ordinary receiver diaphragm. The steel diaphragm 18 is provided -with slots 22 mainly for the purpose of making it light and more sensitive to magnetic influence.

These slots, of which there are two shown in the'` drawings, are, of course,'arranged symmetrically around the center of the diaphragm so thatl the vibration of the diaphragm is uniform.

What l claim is: AH telephone receiver which includes ',a'

.fcuplike shell or casing having an inwardly extending annular flange, a steel diaphragm bearing against the lower face of said flange, a flexible gasket disposed against Y ythe upper face of said ange, a mica ,dia-

phragm bearing, on .said gasket a rigid connection between the steel diaphragm aand the mica diaphragm, 'a exible gasket dispoged on top of and along the edges ofthe mica diaphra a cover plate for said cas,- ing, a depen ent flange on said cover plate extending into said casing and bearing on the second gasket, and means for adjustably fastening the cover plate onto the casina..

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